This invention relates to the field of tissue ablation for the formation of openings in the tissue. In particular, this invention relates to self-removing energy absorbing structures for achieving thermal tissue ablation.
The flux of a drug or analyte across a biological tissue can be increased by changing the diffusion coefficient or the gradient for diffusion. Commonly, the flux is enhanced by increasing the permeability of the skin, such as by chemical penetration enhancers, iontophoresis, and poration techniques.
Thermal tissue ablation for forming openings in tissue is disclosed in commonly assigned U.S. Pat. No. 5,885,211 to Eppstein, et al. There is room for improving the thermal tissue ablation process.
The present invention is directed to a device to facilitate ablation of tissue, such as for forming one or more openings in the tissue for transdermal monitoring and/or delivery applications. The device comprises: (a) a support layer having at least one aperture therein, and (b) at least one energy absorbent film layer disposed over at least one aperture in the support layer for making substantial contact with tissue through the aperture. The at least one energy absorbent film layer is under a tension force over or across the aperture and absorbs energy focused thereon to thermally ablate the tissue. After ablation, and because it is under tension, the film layer breaks apart allowing access to the ablated tissue beneath it.
The present invention is further directed at a method for forming openings in a tissue comprising the steps of: (a) positioning a support layer having an aperture therein on a tissue; (b) positioning an energy absorbent film layer over the aperture to make substantial contact with the tissue through the aperture; and (c) focusing energy onto the energy absorbent film layer to conduct heat to the tissue thereby ablating the tissue.